While some contend that there could exist extr... ...e contend that there could exist extraterrestrial civilizations that have been around for a billion years and the... ...would have heard from them. If there are old civilizations out there, I wonder what one billion year generat... ...ned, if there are...
https://www.neatorama.com/2011/05/17/the-billion-year-technology-gap/
The Billion Year Technology Gap...
Ten Lost Civilizations
By now, I'm sure you've all heard that archeol... ...Southern Spain, but there are plenty more "lost" civilizations out there just begging for discovery. While most... ...op Tenz has a fantastic article about the top ten civilizations that mysteriously disappeared and the stories are...
https://www.neatorama.com/2011/03/24/ten-lost-civilizations/
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